The WU station reporting system will not change. You will be able to view your station data on the map as always. The API key is for companies/corporations who use this data for commercial purposes.
Here is some info I have gleaned through a bit of searching;
WU put out a temporary patch today to fix the no data issue. They have been vocal touting a new interface. lots of info on the WU forum about changes. The WU PWS network is not going away but will be revamped with a new interface, improved graphs and graphics and faster reporting. Some good changes coming. Not so glum a future.
From Tim Roche
HI PWS owners and users. We have implemented a bandaid fix for those of you who were impacted by seemingly missing PWS data over the past few weeks. This issue may pop back up until the new page is launched, which will hopefully happen soon.
I received this this morning from WU
Quote from: WunderTodd (PWS PM) on November 28, 2018, 12:06:23 PM
Hi, thanks for writing.
That's not true.
The Weather Underground API is being shut down in 2019.
The API serves developers and PWS owners who need to access their data for programming and coding.
PWS owners will have access to a new API which will allow them the same access to their data for programming and coding.
The Personal Weather Station network will continue to function as normal.
Developers who use the Weather Underground API will have the option to switch to a Weather Company API which can serve their needs.
We appreciate you being in the community and hope this clarifies what's happening.
Regards,
Todd
About the new interface;
https://www.wunderground.com/redesign/